Treated promptly, the odds are better than the 2am terror suggests: the large majority of GDV dogs reaching surgery in reasonable condition survive, most blockage surgeries go home well, and unblocked cats overwhelmingly recover. The three levers that move every one of those numbers: the clock, the animal's condition on arrival, and whether bowel or stomach wall had already died.
Send what your vet said and quoted. A veterinary surgeon reads it and comes back to you with what they can do and what it would cost, before you pay anything. A written second opinion is from $250.
The happy secret of these surgeries is how completely most animals recover: a GDV survivor with a gastropexy, a dog minus fifteen centimetres of intestine, and a cat with a PU all typically live entirely normal lives. The PU cat trades its blocking risk for a modestly higher urinary infection risk, monitored with occasional urine checks. For owners deciding at the estimate stage, that is the honest other side of the ledger: these are expensive nights that mostly buy whole ordinary lifetimes.
Send the case, hear back from a surgeon with what they can do and what it costs, and only pay if you go ahead.
The spleen travels with the twisting stomach and its vessels can tear or clot; a damaged spleen comes out, and dogs live entirely well without one. Mentioned in advance, it is a sign of a team consenting you properly rather than a surprise on the invoice.
Late deaths after GDV are usually reperfusion injury, heart arrhythmias or tissue that declared itself dead after the surgery, cruel physiology rather than anyone's failure. When the grief settles, a records review can usually reconstruct honestly what happened and whether anything could have gone differently; that is a service we provide with care.